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Jansen HI, van der Steen R, Brandt A, Olthaar AJ, Vesper HW, Shimizu E, Heijboer AC, Van Uytfanghe K, van Herwaarden AE. Description and validation of an equilibrium dialysis ID-LC-MS/MS candidate reference measurement procedure for free thyroxine in human serum. Clin Chem Lab Med 2023; 61:1605-1611. [PMID: 36994743 DOI: 10.1515/cclm-2022-1134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 03/15/2023] [Indexed: 03/31/2023]
Abstract
OBJECTIVES Free thyroxine (FT4) in serum is routinely measured in clinical practice to diagnose and monitor thyroid disease. Due to its concentration in picomolar range and the delicate equilibrium of free and protein-bound T4, accurate measurement is challenging. As a consequence, large inter-method differences in FT4 results exists. Optimal method design and standardization of the FT4 measurement is therefore necessary. The IFCC Working Group for Standardization of Thyroid Function Tests proposed a reference system with a conventional reference measurement procedure (cRMP) for FT4 in serum. In this study, we describe our FT4 candidate cRMP and its validation in clinical samples. METHODS This candidate cRMP is based on equilibrium dialysis (ED) combined with determination of T4 with an isotope-dilution liquid chromatography tandem mass-spectrometry (ID-LC-MS/MS) procedure and was developed according to the endorsed conventions. Its accuracy, reliability, and comparability was investigated using human sera. RESULTS It was shown that the candidate cRMP adhered to the conventions and its accuracy, precision, and robustness were adequate in serum of healthy volunteers. CONCLUSIONS Our candidate cRMP measures FT4 accurately and performs well in serum matrix.
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Affiliation(s)
- Heleen I Jansen
- Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Gastroenterology Endocrinology & Metabolism, Amsterdam, The Netherlands
| | - Rob van der Steen
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - André Brandt
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - André J Olthaar
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hubert W Vesper
- Division of Laboratory Sciences, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Eri Shimizu
- Reference Material Institute for Clinical Chemistry Standards, Yokohama, Kanagawa, Japan
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC Location Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Gastroenterology Endocrinology & Metabolism, Amsterdam, The Netherlands
- Amsterdam Reproduction & Development Research Institute, Amsterdam, The Netherlands
| | - Katleen Van Uytfanghe
- Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Laboratory of Toxicology, Ref4U, Ghent University, Ghent, Belgium
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2
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Adriaansen BPH, Kamphuis JS, Schröder MAM, Olthaar AJ, Bock C, Brandt A, Stikkelbroeck NMML, Lentjes EGWM, Span PN, Sweep FCGJ, Claahsen‐van der Grinten HL, van Herwaarden AE. Diurnal salivary androstenedione and 17-hydroxyprogesterone levels in healthy volunteers for monitoring treatment efficacy of patients with congenital adrenal hyperplasia. Clin Endocrinol (Oxf) 2022; 97:36-42. [PMID: 35150157 PMCID: PMC9542109 DOI: 10.1111/cen.14690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Treatment of congenital adrenal hyperplasia (CAH) patients with glucocorticoids is often challenging since there is a delicate balance between over- and undertreatment. Treatment can be monitored noninvasively by measuring salivary androstenedione (A4) and 17-hydroxyprogesterone (17-OHP). Optimal treatment monitoring requires the establishment of reference values in saliva. DESIGN A descriptive study. PATIENTS For this study saliva of 255 healthy paediatric and adult volunteers with an age range of 4-75 years old was used. MEASUREMENTS We developed a sensitive liquid chromatography-tandem mass spectrometry method, assessed salivary A4 and 17-OHP stability, and measured A4 and 17-OHP concentrations in saliva collected in the morning, afternoon, and evening. RESULTS We quantified A4 and 17-OHP concentrations in the morning, afternoon, and evening and demonstrated that there is a significant rhythm with the highest levels in the morning and decreasing levels over the day. A4 and 17-OHP concentrations display an age-dependent pattern. These steroids remain stable in saliva at ambient temperature for up to 5 days. CONCLUSIONS Good stability of the steroids in saliva enables saliva collection by the patient at home. Since salivary A4 and 17-OHP display a diurnal rhythm and age-dependent pattern, we established reference values for both children and adults at three time points during the day. These reference values support treatment monitoring of children and adults with CAH.
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Affiliation(s)
- Bas P. H. Adriaansen
- Department of Laboratory Medicine, Radboud Institute of Health SciencesRadboud University Medical CentreNijmegenThe Netherlands
- Department of Paediatric Endocrinology, Amalia Children's HospitalRadboud University Medical CentreNijmegenThe Netherlands
| | - Johannes S. Kamphuis
- Department of Clinical Chemistry and HaematologyGelre HospitalsApeldoornThe Netherlands
| | - Mariska A. M. Schröder
- Department of Paediatric Endocrinology, Amalia Children's HospitalRadboud University Medical CentreNijmegenThe Netherlands
- Department of Laboratory Medicine, Radboud Institute of Molecular Life SciencesRadboud University Medical CentreNijmegenThe Netherlands
| | - André J. Olthaar
- Department of Laboratory Medicine, Radboud Institute of Health SciencesRadboud University Medical CentreNijmegenThe Netherlands
| | - Carina Bock
- Department of Laboratory Medicine, Radboud Institute of Health SciencesRadboud University Medical CentreNijmegenThe Netherlands
| | - André Brandt
- Department of Laboratory Medicine, Radboud Institute of Health SciencesRadboud University Medical CentreNijmegenThe Netherlands
| | | | - Eef G. W. M. Lentjes
- Central Diagnostic LaboratoryUniversity Medical Centre UtrechtUtrechtThe Netherlands
| | - Paul N. Span
- Department of Radiation OncologyRadboud University Medical CentreNijmegenThe Netherlands
| | - Fred C. G. J. Sweep
- Department of Laboratory Medicine, Radboud Institute of Health SciencesRadboud University Medical CentreNijmegenThe Netherlands
| | | | - Antonius E. van Herwaarden
- Department of Laboratory Medicine, Radboud Institute of Health SciencesRadboud University Medical CentreNijmegenThe Netherlands
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Driessen JMA, Brazil IA, Lorenzo ED, Herwaarden AE, Olthaar AJ, Potamianou H, Glennon JC. Psychopathic traits influence threat avoidance in a community sample independent of testosterone. Personal Disord 2021; 12:428-436. [PMID: 33793258 DOI: 10.1037/per0000481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Psychopathy is a personality construct that encompasses a constellation of traits reflecting emotional dysfunction and antisocial behavior. Individuals with elevated levels of psychopathic traits have shown abnormal affective processing. Studies with psychopathic offenders suggested that this is a result of altered automatic social approach-avoidance tendencies. The goal of the current study was to increase the insight into the underlying mechanism of affective processes in community-dwelling individuals with a high level of psychopathic traits by studying approach and avoidance behavior in an experimental setting. Furthermore, given its link with aggression and threat approach, testosterone was measured to investigate a possible mediatory role. Eighty-seven healthy individuals performed a computerized affective approach-avoidance task in which they pushed or pulled emotional faces using a joystick. The results showed that high levels of psychopathic traits corresponded with diminished threat avoidance to angry faces, as was found previously in psychopathic offenders. Although endogenous testosterone was positively associated with the level of psychopathic traits, it did not mediate the effect of psychopathic traits on threat avoidance. We propose that an increased understanding of the interplay between different neuroendocrine mechanisms could lead to a better insight into the underlying mechanism of abnormal threat avoidance in individuals with high levels of psychopathic traits. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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Affiliation(s)
- Josi M A Driessen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University
| | - Inti A Brazil
- Donders Institute for Brain, Cognition and Behaviour, Radboud University
| | | | - Antonius E Herwaarden
- Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center
| | - André J Olthaar
- Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center
| | - Hera Potamianou
- Donders Institute for Brain, Cognition and Behaviour, Radboud University
| | - Jeffrey C Glennon
- Donders Institute for Brain, Cognition and Behaviour, Radboud University
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4
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Schuijt MP, Sweep CGJ, van der Steen R, Olthaar AJ, Stikkelbroeck NMML, Ross HA, van Herwaarden AE. Validity of free testosterone calculation in pregnant women. Endocr Connect 2019; 8:672-679. [PMID: 31035253 PMCID: PMC6528408 DOI: 10.1530/ec-19-0110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 04/29/2019] [Indexed: 11/27/2022]
Abstract
Objective Increased maternal testosterone concentration during pregnancy may affect the fetus. Therefore it is clinically relevant to have a quick and reliable method to determine free testosterone levels. Current calculators for free testosterone are suspected to perform poorly during pregnancy due to suggested competition between high levels of estradiol and free (bio-active) testosterone for sex hormone-binding globulin (SHBG) binding. Therefore, it is claimed that reliable calculation of free testosterone concentration is not possible. However, recent evidence on SHBG-binding sites questions the estradiol effect on the testosterone-SHBG binding during pregnancy. In this study, we investigated whether the free testosterone concentration can be calculated in pregnant women. Design and methods Free testosterone was measured with a specially developed equilibrium dialysis method combined with liquid chromatography tandem mass spectrometry (LC-MS/MS). Free testosterone was also calculated with the formulas of Vermeulen et al. and Ross et al. Results Total and free testosterone measured in healthy men and women were in good agreement with earlier reports. In pregnant women, total testosterone values were higher than in non-pregnant women, whereas free testosterone values were comparable. Calculated free testosterone levels in pregnant women were highly correlated, but marginally higher, compared to measured free testosterone levels. Conclusions We developed an equilibrium dialysis-LC-MS/MS method for the measurement of free testosterone in the low range of pregnant and non-pregnant women. Although during pregnancy total testosterone is increased, this is not the case for free testosterone. The free testosterone formulas perform well in pregnant women.
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Affiliation(s)
- M P Schuijt
- Department of Laboratory Medicine, Slingeland Hospital, Doetinchem, The Netherlands
- Department of Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - C G J Sweep
- Department of Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - R van der Steen
- Department of Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - A J Olthaar
- Department of Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - N M M L Stikkelbroeck
- Division of Endocrinology, Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - H A Ross
- Department of Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - A E van Herwaarden
- Department of Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
- Correspondence should be addressed to A E van Herwaarden:
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5
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Gubbels CS, Thomas CMG, Wodzig WKWH, Olthaar AJ, Jaeken J, Sweep FCGJ, Rubio-Gozalbo ME. FSH isoform pattern in classic galactosemia. J Inherit Metab Dis 2011; 34:387-90. [PMID: 20814826 PMCID: PMC3063565 DOI: 10.1007/s10545-010-9180-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 05/19/2010] [Accepted: 07/19/2010] [Indexed: 11/27/2022]
Abstract
Female classic galactosemia patients suffer from primary ovarian insufficiency (POI). The cause for this long-term complication is not fully understood. One of the proposed mechanisms is that hypoglycosylation of complex molecules, a known secondary phenomenon of galactosemia, leads to FSH dysfunction. An earlier study showed less acidic isoforms of FSH in serum samples of two classic galactosemia patients compared to controls, indicating hypoglycosylation. In this study, FSH isoform patterns of five classic galactosemia patients with POI were compared to the pattern obtained in two patients with a primary glycosylation disorder (phosphomannomutase-2-deficient congenital disorders of glycosylation, PMM2-CDG) and POI, and in five postmenopausal women as controls. We used FPLC chromatofocussing with measurement of FSH concentration per fraction, and discovered that there were no significant differences between galactosemia patients, PMM2-CDG patients and postmenopausal controls. Our results do not support that FSH dysfunction due to a less acidic isoform pattern because of hypoglycosylation is a key mechanism of POI in this disease.
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Affiliation(s)
- Cynthia S. Gubbels
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Chris M. G. Thomas
- Laboratory of Genetic, Endocrine and Metabolic Diseases, Department of Laboratory Medicine and Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Will K. W. H. Wodzig
- Department of Clinical Chemistry, Maastricht University Medical Center, Maastricht, The Netherlands
| | - André J. Olthaar
- Laboratory of Genetic, Endocrine and Metabolic Diseases, Department of Laboratory Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Jaak Jaeken
- Center for Metabolic Disease, University Hospital Gasthuisberg, Leuven, Belgium
| | - Fred C. G. J. Sweep
- Laboratory of Genetic, Endocrine and Metabolic Diseases, Department of Laboratory Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - M. Estela Rubio-Gozalbo
- Department of Pediatrics and Laboratory of Inherited Metabolic Diseases, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
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6
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Oei ALM, Sweep FCGJ, Massuger LFAG, Olthaar AJ, Thomas CMG. Transient human anti-mouse antibodies (HAMA) interference in CA 125 measurements during monitoring of ovarian cancer patients treated with murine monoclonal antibody. Gynecol Oncol 2008; 109:199-202. [PMID: 18304620 DOI: 10.1016/j.ygyno.2008.01.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 01/09/2008] [Accepted: 01/18/2008] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the influence of human anti-mouse antibodies (HAMA) on serial CA 125 measurements in serum of patients with epithelial ovarian cancer following single intraperitoneal (IP) therapy with Yttrium-90-labeled human milk fat globule 1 murine monoclonal antibody ((90)Y-muHMFG1) as part of a large international randomized phase III trial. METHODS We monitored CA 125 concentrations in longitudinally collected serum samples from 224 patients after IP (90)Y-muHMFG1 (study group) and from 223 patients who received standard treatment (control group). Serum samples of 22 study patients with increased CA 125 concentrations were selected and subjected to affinity chromatography to study HAMA interference in CA 125 measurements. RESULTS CA 125 serum concentrations at weeks 1, 4 and 8 were significantly higher in the study group than in the control group. In the first 8 weeks after IP (90)Y-muHMFG1 administration significantly more patients of the study group (144/224) demonstrated CA 125 concentrations above the upper limit of normal of 23 U/mL, as compared to those of the control group (37/223). Affinity chromatography of serum with high CA 125 values in the first 8 weeks confirmed HAMA interference in CA 125 measurements while after 24 weeks this HAMA interference could no longer be detected. CONCLUSIONS This is the first study to demonstrate that clinical trials applying murine monoclonal antibodies may be flawed by a transient HAMA effect, which should be considered when monitoring ovarian cancer patients with CA 125 measurements.
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Affiliation(s)
- Angèle L M Oei
- Department of Obstetrics and Gynecology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
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7
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Mulder AH, Tack CJ, Olthaar AJ, Smits P, Sweep FCGJ, Bosch RR. Adrenergic receptor stimulation attenuates insulin-stimulated glucose uptake in 3T3-L1 adipocytes by inhibiting GLUT4 translocation. Am J Physiol Endocrinol Metab 2005; 289:E627-33. [PMID: 15914506 DOI: 10.1152/ajpendo.00079.2004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Activation of the sympathetic nervous system inhibits insulin-stimulated glucose uptake. However, the underlying mechanisms are incompletely understood. Therefore, we studied the effects of catecholamines on insulin-stimulated glucose uptake and insulin-stimulated translocation of GLUT4 to the plasma membrane in 3T3-L1 adipocytes. We found that epinephrine (1 microM) nearly halved insulin-stimulated 2-deoxyglucose uptake. The beta-adrenoceptor antagonist propranolol (0.3 microM) completely antagonized the inhibitory effect of epinephrine on insulin-stimulated glucose uptake, whereas the alpha-adrenoceptor antagonist phentolamine (10 microM) had no effect. When norepinephrine was used instead of epinephrine, the results were identical. None of the individual selective beta-adrenoceptor antagonists (1 microM, beta(1): metoprolol, beta(2): ICI-118551, beta(3): SR-59230A) could counteract the inhibitory effect of epinephrine. Combination of ICI-118551 and SR-59230A, as well as combination of all three selective beta-adrenoceptor antagonists, abolished the effect of epinephrine on insulin-stimulated glucose uptake. After differential centrifugation, we measured the amount of GLUT1 and GLUT4 in the plasma membrane and in intracellular vesicles by means of Western blotting. Both epinephrine and norepinephrine reduced insulin-stimulated GLUT4 translocation to the plasma membrane. These results show that beta-adrenergic (but not alpha-adrenergic) stimulation inhibits insulin-induced glucose uptake in 3T3-L1 adipocytes, most likely via the beta(2)- and beta(3)-adrenoceptor by interfering with GLUT4 translocation from intracellular vesicles to the plasma membrane.
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Affiliation(s)
- Alexandra H Mulder
- Division of General Internal Medicine, Radboud University, Nijmegen Medical Centre, NL-6500 HB Nijmegen, The Netherlands
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Bosch RR, Bazuine M, Span PN, Willems PHGM, Olthaar AJ, van Rennes H, Maassen JA, Tack CJ, Hermus ARMM, Sweep CGJF. Regulation of GLUT1-mediated glucose uptake by PKClambda-PKCbeta(II) interactions in 3T3-L1 adipocytes. Biochem J 2005; 384:349-55. [PMID: 15307820 PMCID: PMC1134118 DOI: 10.1042/bj20040797] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Members of the PKC (protein kinase C) superfamily play key regulatory roles in glucose transport. How the different PKC isotypes are involved in the regulation of glucose transport is still poorly defined. PMA is a potent activator of conventional and novel PKCs and PMA increases the rate of glucose uptake in many different cell systems. In the present study, we show that PMA treatment increases glucose uptake in 3T3-L1 adipocytes by two mechanisms: a mitogen-activated protein kinase kinase-dependent increase in GLUT1 (glucose transporter 1) expression levels and a PKClambda-dependent translocation of GLUT1 towards the plasma membrane. Intriguingly, PKClambda co-immunoprecipitated with PKCbeta(II) and did not with PKCbeta(I). Previously, we have described that down-regulation of PKCbeta(II) protein levels or inhibiting PKCbeta(II) by means of the myristoylated PKCbetaC2-4 peptide inhibitor induced GLUT1 translocation towards the plasma membrane in 3T3-L1 adipocytes. Combined with the present findings, these results suggest that the liberation of PKClambda from PKCbeta(II) is an important factor in the regulation of GLUT1 distribution in 3T3-L1 adipocytes.
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Affiliation(s)
- Remko R Bosch
- Department of Chemical Endocrinology, University Medical Centre Nijmegen, Nijmegen, The Netherlands.
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Bosch RR, Pouwels MJJM, Span PN, Olthaar AJ, Tack CJ, Hermus ARMM, Sweep CGJ. Hexosamines are unlikely to function as a nutrient-sensor in 3T3-L1 adipocytes: a comparison of UDP-hexosamine levels after increased glucose flux and glucosamine treatment. Endocrine 2004; 23:17-24. [PMID: 15034192 DOI: 10.1385/endo:23:1:17] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2003] [Revised: 12/12/2003] [Accepted: 12/22/2003] [Indexed: 11/11/2022]
Abstract
Whether the hexosamine biosynthesis pathway acts as a nutrient-sensing pathway is still unclear. Glucose is directed into this pathway by GFAT. Because the activity of GFAT is tightly regulated, we examined whether UDP-hexosamine levels can increase significantly and dose-dependently in response to elevated glucose concentrations. In glucosamine-treated 3T3-L1 adipocytes, inhibition of insulin-stimulated glucose uptake was highly correlated with UDP-hexosamine levels (r = -0.992; p < 0.0001 for UDP-GlcNAc and r = -0.996; p < 0.0001 for UDP-GalNAc). Incubation of 3T3-L1 adipocytes with 0.1 microM insulin for 24 h in medium containing 1 and 5 mM glucose increased the rate of glucose uptake by 365% and 175% compared to untreated cells, respectively. This increase was not observed when the cells were incubated for 24 h with insulin in medium containing 10 or 25 mM glucose. However, treatment of cells with insulin and 1, 5, 10, or 25 mM glucose resulted in similar increases in levels of UDP-GlcNAc and UDP-GalNAc that always amounted to approx 30-40% above baseline values. This led us to conclude that despite exposure of adipocytes to conditions of extreme and prolonged glucose disposal, the increases in cellular UDP-hexosamines were minimal and not dependent on the extracellular glucose concentration. Taken together, our results are in line with the hypothesis that in glucosamine-treated adipocytes UDP-hexosamines influence insulin-stimulated glucose uptake. However, our observations in glucose-treated adipocytes argue against the possibility that UDP-hexosamines function as a nutrient-sensor, and question the role of the hexosamine biosynthesis pathway in the pathogenesis of insulin resistance.
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Affiliation(s)
- Remko R Bosch
- Department of Chemical Endocrinology, University Medical Centre Nijmegen, The Netherlands.
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10
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Bosch RR, Bazuine M, Wake MM, Span PN, Olthaar AJ, Schürmann A, Maassen JA, Hermus ARMM, Willems PHGM, Sweep CGJ. Inhibition of protein kinase CbetaII increases glucose uptake in 3T3-L1 adipocytes through elevated expression of glucose transporter 1 at the plasma membrane. Mol Endocrinol 2003; 17:1230-9. [PMID: 12702734 DOI: 10.1210/me.2003-0057] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The mechanism via which diacylglycerol-sensitive protein kinase Cs (PKCs) stimulate glucose transport in insulin-sensitive tissues is poorly defined. Phorbol esters, such as phorbol-12-myristate-13-acetate (PMA), are potent activators of conventional and novel PKCs. Addition of PMA increases the rate of glucose uptake in many different cell systems. We attempted to investigate the mechanism via which PMA stimulates glucose transport in 3T3-L1 adipocytes in more detail. We observed a good correlation between the rate of disappearance of PKCbetaII during prolonged PMA treatment and the increase in glucose uptake. Moreover, inhibition of PKCbetaII with a specific myristoylated PKCbetaC2-4 peptide inhibitor significantly increased the rate of glucose transport. Western blot analysis demonstrated that both PMA treatment and incubation with the myristoylated PKCbetaC2-4 pseudosubstrate resulted in more glucose transporter (GLUT)-1 but not GLUT-4 at the plasma membrane. To our knowledge, we are the first to demonstrate that inactivation of PKC, most likely PKCbetaII, elevates glucose uptake in 3T3-L1 adipocytes. The observation that PKCbetaII influences the rate of glucose uptake through manipulation of GLUT-1 expression levels at the plasma membrane might reveal a yet unidentified regulatory mechanism involved in glucose homeostasis.
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Affiliation(s)
- Remko R Bosch
- Department of Chemical Endocrinology, University Medical Centre, 6500 HB Nijmegen, The Netherlands.
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11
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Pouwels MJJ, Span PN, Tack CJ, Olthaar AJ, Sweep CGJF, van Engelen BG, de Jong JG, Lutterman JA, Hermus AR. Muscle uridine diphosphate-hexosamines do not decrease despite correction of hyperglycemia-induced insulin resistance in type 2 diabetes. J Clin Endocrinol Metab 2002; 87:5179-84. [PMID: 12414889 DOI: 10.1210/jc.2002-020440] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Animal studies suggest that overactivity of the hexosamine pathway, resulting in increased UDP-hexosamines [UDP-N-acetylglucosamine (UDP-GlcNAc) and UDP-N-acetylgalactosamine (UDP-GalNAc)] is an important mechanism by which hyperglycemia causes insulin resistance. This study was performed to test this hypothesis in patients with type 2 diabetes mellitus (DM). Eight obese patients with uncontrolled DM type 2 and severe insulin resistance were treated with iv insulin for 28 +/- 6 d aimed at euglycemia. Before and after iv insulin treatment, insulin sensitivity was measured using a hyperinsulinemic euglycemic clamp, and a muscle biopsy was taken for measurement of UDP-GlcNAc, UDP-GalNAc, UDP-glucose, and UDP-galactose levels. Also, isoelectric focusing patterns of serum transferrin and the urinary excretion of glycosaminoglycans as measures of final products of the hexosamine pathway were examined. After euglycemia, insulin resistance improved, as demonstrated by an increase in the glucose infusion rate during the clamp from 12.7 +/- 5.6 to 22.4 +/- 8.8 micro mol/kg.min (P < 0.0005) and a decrease in insulin requirement from 1.7 +/- 0.9 to 1.1 +/- 0.6 U/kg.d (P < 0.005), whereas metabolic control improved. Surprisingly, both UDP-GlcNAc, from 8.81 +/- 1.21 to 12.31 +/- 2.52 nmol/g tissue (P < 0.005), and UDP-GalNAc concentrations, from 4.49 +/- 0.85 to 5.89 +/- 1.55 nmol/g tissue (P < 0.05) increased. Isoelectric focusing patterns of serum transferrin and excretion of glycosaminoglycans were similar before and after euglycemia. In conclusion, after amelioration of hyperglycemia- induced insulin resistance, UDP-hexosamines increased in skeletal muscle of patients with type 2 DM. These results do not support the hypothesis that accumulation of products of the hexosamine pathway plays a major role in hyperglycemia-induced insulin resistance.
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Affiliation(s)
- Marie-Jose J Pouwels
- Division of General Internal Medicine, Department of Medicine, University Medical Center, 6500 HB Nijmegen, The Netherlands.
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12
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Span PN, Pouwels MJ, Olthaar AJ, Bosch RR, Hermus AR, Sweep CG. Assay for hexosamine pathway intermediates (uridine diphosphate-N-acetyl amino sugars) in small samples of human muscle tissue. Clin Chem 2001; 47:944-6. [PMID: 11325903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- P N Span
- Departments of Chemical Endocrinology, University Medical Centre Nijmegen, 6500 HB Nijmegen, The Netherlands.
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Koper NP, Thomas CM, Massuger LF, Segers MF, Olthaar AJ, Verbeek AL. Quantitation of IgG and IgM human anti-mouse antibodies (HAMA) interference in CA 125 measurements using affinity chromatography. Clin Chem Lab Med 1998; 36:23-8. [PMID: 9594082 DOI: 10.1515/cclm.1998.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Currently no available immunoassay system offers complete protection against spuriously elevated or lowered results due to interference by Human Anti-Mouse Antibodies (HAMA). Although routine use of chromatography procedures is not an acceptable option because of the extra cost and workload involved, such a procedure would be highly desirable to ensure accurate immunoassay results. The present report describes a relatively simple affinity chromatography procedure using a HiTrap Protein G column to isolate immunoglobulin G (IgG) HAMA, followed by a HiTrap N-hydroxy-succinimide (NHS)-activated column coupled to goat-anti human immunoglobulin M (IgM) to bind IgM HAMA. To examine the usefulness of this purification procedure we determined CA 125 in forty serum samples prior to and following chromatography. Pre- and post-injection samples were obtained from 20 patients injected with 1 mg of 111In-labelled murine OC 125 F(ab')2 fragments in an immunoscintigraphy study. It is shown that this analytical procedure provides a technique to determine the extent and the nature of the existing HAMA interference in samples of patients after in vivo use of monoclonal antibodies for diagnostic or therapeutic purposes. The procedure can also contribute to the clarification of clinically discordant CA 125 results. Finally, the availability of such a procedure in the clinical laboratory provides an opportunity to test the robustness of newly developed immunoassay systems towards HAMA interference.
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Affiliation(s)
- N P Koper
- Department of Obstetrics and Gynaecology, University of Nijmegen, The Netherlands
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